NRPN to DSI Prophet 08

I'm using a DSI Prophet 08. I would like a way, from Live, to toggle local mode on and off. Ideally, i just want a M4L MIDI effect which displays a panel with a toggle button that will allow me to turn this mode on or off.

The Prophet supports this through the use of NRPN.

From the manual:

Pram:    7
NRPN:    389
Value:     1 On : 0 Off

I'm not having a lot of luck sending NRPN data. First, admittedly, I'm a bit new to M4L, so I'm not sure what I'm doing. Secondly, most of the examples are using ctlout, which from my understanding, requires port info as part of the argument. M4L seems to be using a midiout to send output to the "current" port / channel, which would be idea. I just need to figure out how to construct and send the correct message. Furthermore, many of the examples seem to be a bit older, and not specific to M4L.

Can anyone give me guidance on:
1. How to send NRPN from M4L
2. How to do so without requiring the user to define the port.

Thanks,
Dan